A conventional transfortable container, which is typically used for containing and transporting materials, such as beverages, alcoholic liquors and fruits etc., requires much costs and spaces in transforting and storaging thereof due to maintaining the original volumn and shapes even when empty. Therefore, there have been proposed various kinds of foldable containers.
For example, DE 41 09 151 discloses a square, transportable container having a base onto which four side walls flap down when the container is empty. The first pair of facing side walls lie directly on the base and the second pair of opposite side walls rest on the first pair. The hinge axes of the side walls are positioned at different heights above the base. The side walls standed up are connected together by hook mechanism provided on them to form box shape of the container. The hook mechanism has disadvantages that locking and unlocking operation thereof is inconvenient and time-consuming and the cost therefor is relatively high.
Another fold able container is disclosed in EP 443 327 A2. This container has a construction basically similar to that of the container disclosed in DE 41 09 151, but the connection mechanism between adjacent side walls comprises L-shaped edge connecting elements of U-shape in section having fillets engaging with recesses on the top faces of the side walls. The connecting elements engage with both of the adjacent side walls to secure them integrally. However, because the connecting elements are separated from the container body, it is easy to miss the connecting elements when the container is folded down and the connecting using them is relatively inconvenient.